Tape recording and translation, and the like



N0V 30, 1965 T. A. BANNING, JR., ETAL 3,221,336

TAPE RECORDING AND TRANSLATION, AND THE LIKE Direction of-IZLEeTrovei.

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NOV 30, 1955 T. A. BANNING, JR.. ETAL. 3,221,336

TAPE RECORDING AND TRANSLATION, AND THE LIKE United States Patent O3,221,336 TAPE RECORDING AND TRANSLATION, AND THE LIKE Thomas A.Banning, Jr., Chicago, Ill., and Emil L. Ranseen, deceased, late ofChicago, Ill., by Agnes J. Ranseen, executrix, Evanston, Ill.; saidAgnes J. Ranseen assignor to said Banning Original application May 4,1954, Ser. No. 427,425, now Patent No. 2,976,354, dated Mar. 21, 1961.Divided and this application Mar. 9, 1961, Ser. No. 94,652

Claims. (Cl. 346--74) =T his invention relates to improvements in taperecording and translation, and the like. Broadly stated, theseimprovements relate to improvements in cross-scanning tape recording andtranslation; and specifically, they relate to cross-scanning ltaperecording and translation with use of magnetic type tape. Thisapplication is a division of the parent application of Thomas A.Banning, Jr., and Emil L. Ranseen, now deceased, for Improvements inTape Recording and Translating, and the Like, Serial No. 427,428, filedMay 4, 1954, and issued as Letters Patent of the United States, No.2,976,354, March 21, 1961. In that parent application and patent thereis disclosed means to produce and to interpret signals in cross-scanningarrangement on the magnetizable tape, wherein the cross-scans areproduced by use of an electronic unit which includes a deilectable beamand means to produce the deflections of such beam under control, withimpingement of the beam against an elongated target, and either with orwithout modulation of the beam during such cross-scans. That parent casealso discloses means to produce at the exterior of the envelope of theelectronic unit, a force which traverses the width of tape which carriesthe cross-scans, following the deflections of the beam within theenvelope; and also discloses means such that the strength of the forcethus produced exterior to the envelope, and which follows the beamscans, is always proportional to the strength of the beam within theenvelope. During recording operations the beam strength is modulated, ifnecessary, according to the strengths of signals to be recorded; duringtranslation from the tape of previously recorded signals, and accordingto certain disclosures of that parent application and patent, the beamstrength within the envelope is retained constant, and provision is madefor producing a translation signal proportional to the combinedstrengths of the recorded signals and the strength of the beam withinthe envelope.

That earlier application and patent also discloses means to produce theforce which is exterior to the envelope, by provision of a series ofelectrical conductors, extending through the -envelope from locationsalong the target, to locations exterior to the envelope, and inproximity to the tape surface and in alignment proper to produce or tosense the signals to `be recorded on the tape, or to be sensed andtranslated from the tape during a play-back operation. This arrangementis such that as the beam deections occur under control, and either withor Without modulation of the beam strength, the beam impinges suc:cessively with the conductor portions which are within the envelope,thus electrifying them proportionately to the strength of the beam Iatsuch impingement location. Thus, electrifying actions are also producedto the conductor portions outside of the envelope, for conduct of eitherthe recording or the sensing and translating operations.

The present application relates to improved means to translate theelectrifying signals produced on and through the conductors which extendthrough the envelope of the electron unit, into improved magnetizingeffects produced on the tape during a recording operation; or toVimproved sensing effects produced by the previously recorded magneticsignals carried by the tape, and which when sensed are properlyamplified and translated as desired. In the former case-that oftranslating the electrifying signals produced on and through theconductors, for improved magnetizing effects on the tape-there isprovided a minute magnetizing coil carried close to the tape surface, orin contact therewith during tape travel, corresponding to each of theconductors which extend through the envelope, together with suitablecircuitry for providing a circuit through each such minute coil, duringthe short instant that the deflectable beam is in contact with the endof the conductor within the envelope. The magnitude of the current whichwi-ll then flow through each such coil during deflection of the beam,will depend on the beam strength at the instant of beam impingement oneach such conductor. Thus, there will be produced on the tape, duringeach beam scan, a series of magnetized elemental areas, lyingsuccessively along the line of scan ofthe tape, and successively ofstrengths proportional to the beam strengths at the instants ofproduction of such elemental areas. Accordingly, such arrangementprovidesl means to amplify the magnetized elemental area strengthsproportionately to the increased magnetizing effect produced by suchcoils, as compared with the magnetizing effect produced by otherarrangements.

It is also an object of the invention to amplify the strength of thebeam which impinges against the end of each conductor within theenvelope, by amplifying means, such as dynode means, as hereinafterdisclosed.

In the case of producing improved sensing effects from previouslyrecorded magnetic signals, namely, that of translating the previouslyrecorded variations of magnetism carried by the tape on scans extendingacross such tapethere is provided, corresponding to each of theconductors which extend through the envelope, a minute conductorextending in close proximity to or even in contact with, the tapesurface in direction such that the travel of the tape will induce, bythe magnetic strength previously recorded at the location of such minuteconductor across the tape width, an proportionate to the strength ofsuch magnetism. Proper circuitry is also provided for transferring, andamplifying, the signal thus induced corresponding to such elemental tapescan area.

If desired, means may be provided for y.amplifying the effects producedby such sensing arrangement; such amplifying arrangement, being forexample, by use of dynode means in position to amplify the sensedeffect, or to produce a base of potential above which the sensed israised.

A further feature and object of the invention relates to the provisionof means to mount the minute magnetizing coils or the minute sensingconductors, such that these small elements may be retained againstdeformation, and may be firmly secured to the electronic unit and heldin place without deformations which might otherwise be produced, due totheir minute size and small physical strengths. This feature alsoincludes conven-ient means to manufacture such elements into sets forready attachment to the electronic units with which they are to be used.

Other objects and uses of the invention will appear from a detaileddescription of the same, 'which consists in the features of constructionand combinations of parts herein- Iafter described and claimed.

In the drawings:

FIGURE 1 shows a section of tape whereon a recording is mademagnetically, with use of the cross-scan arrangement, but with the useof the conductor arrangement for transferring the controls from theelectron beam inside of the envelope to suitable magnetizing elementsoutside `of the envelope; and this figure shows the tape carrying themagnetizable material with provision for first subjeeting suchmagnetizable material to a pre-magnetized effect to ensure provision ofa uniform amount of magnetic effect -on the tape surface, together withthe scanning tube arrangement and the magnetizing devices for thereafterproducing on the so-prepared tape surface the desired modulations ofmagnetization;

FIGURE 2 shows an edge View corresponding to FIG- URE 1; and this figureshows in outline the presence of the magnetizing coils (of very smallsize) outside of the tube envelope, each coil being connected to one ofthe conductors which extend through the envelope and whose inner endsare subject to impingement by the electron beam during its scan-ningswings;

FIGURE 3 shows a cross-section taken on the line 3 3 of FIGURE 2,looking in the direction of the arrows; and this figure shows the lowerends of the conductors which extend through the lower portion `of thescanning tube as being individually in connection with the minutemagnetizing coils which are located close to the tape surface;

FIGURE 4 shows a cross-section taken on the line 4 4 of FIGURE 2,looking in the direction of the arrows; and this figure shows thepre-magnetizing unit for placing a magnetization on the tape of uniformintensity over the entire tape surface prior to the subjecting lof anyelemental area of the tape surface to the magnetization modulatingeffect Iof the scanning tube coil in alignment with such elemental area;

FIGURE 5 shows a bottom end view of the scanning tube, together with theminute magnetizing coils which are connected to the ends of theconductors extending through the tube envelope, the free ends of allsuch minute coils being connected to a common return line as shown inthis figure;

FIGURE 6 shows on greatly enlarge-d scale lone end portion of the lowerportion of the scanning tube, together with the magnetizing coil unitportion adjacent to, such tube end, such magnetizing coil unitcomprising a block of synthetic material having the coils embedded andmoulded in such block, with their ends properly connected to the commonreturn line, and to the individual conductors which extend through thetube end;

FIGURE 7 shows a cross-section taken on the line 7-7 of FIGURE 6,looking in the direction of the arrows;

FIGURE 8 shows a section of the magnetizable material tape carrying themagnetic cross-scan signal variations, and also carrying a magneticallyproduced sound track, and the magnetically produced synchronizing sig-4nals along one edge portion of the tube;

FIGURE 9 shows an edge view corresponding to FIG- URE 8; and this figureshows the minute sensing conductors which are located in regular spacingacross the width of the scanned and recorded area, and which areVelectromagnetically influenced by the travelling tape to produce thedesired sensing effects, which effects are then amplified and translatedas desired;

FIGURE 10 shows a cross-section taken on the line 10-10 of FIGURE 9,looking in the direction of the arrows; and this figure shows thesensing conductors previously referred to and which are carried by asensing block at the lower end of the scanning tube;

FIGURE 1l shows a bottom -face View of the scanning tube of FIGURES 9and 10; and this figure shows the minute sensing conductors located inalignment across the width of the cross-scan recorded portion of thetape; and one end of each such sensing conductor is connected to one ofthe conductor wires extending through the tube envelope and the freeends of these scanning conductors are all connected to a common linewhich may be used for delivering the sensed effects of the unit tosuitable amplifying and translating units as desired;

FIGURE 12 shows on greatly enlarged scale one end portion of the lowerportion of the scanning tube; and it shows the block of syntheticmaterial in which the minute sensing conductors may be embedded ormoulded in suitable manner;

FIGURE 13 shows a cross-section taken `on the line 13a-13 -of FIGURE 12,looking in the direction of the arrows; and

FIGURE 14 shows, schematically, a simple form of wiring connections fordelivering the sensed effects from the minute sensing conductors to acommon amplifying and interpreting unit lor units.

In both of the units shown in FIGURES 1 to 7, inclusive, and FIGURES 8to 14, inclusive there is shown a deflectable beam electronic unitsupported vertically in position above the magnetic surfaced materialtape; and such tape is mounted for endwise movement under suitabledrive, according to conventional magnetic tape recording practice.Examination of each of FIGURES 1, 3, 4, 8, and 10 shows that such tapeis of width suflicient to accommodate cross-scans produced by one of theillustrated units (that of FIGURES 1 to 7, inclusive), and sensed by theother such unit (that of FIGURES 8 to 14, inclusive). The details ofsuch cross-scanning are fully disclosed in said patent application,issued patent, No. 2,976,354; accordingly, it is not deemed necessary tonclude further details of such operations here, except as thedisclosures of the present case relat-e to certain details ofconstruction and operation of certain of the embodiments of that parentcase.

It is also noted that each of the showings of the figures hereinincluded, includes an electronic unit which is supported vertically withrespect to the horizontally travelling tape, so that the closed end ofsuch units envelope is brought close to the tape surface, being thatenvelope en'd at which the target lof the deflectable beam is located.The present embodiments are not, however, limited to use in connectionwith such vertically mounted electronic unit, except as limitations maybe imposed by the claims to follow. These vertical showings, however,are of simple construction since the deflectable beam does not requirechange of its longitudinal direction, beyond the conventional lateraldeflections produced by conventional deflection yokes or other elementsneeded to produce such deflections.

Referring first to each of FIGURES 3 and 10 it is seen that the lower orscanning end of each of the electronic beam units is of width suflcientto accommodate the desired scan across the width of the tape to carrythe cross-scanned signal recordings; and thus each of such unitsenvelopes is of generally triangular form, with its broad end proximateto the tape surface.

The upper or neck portion of each such unit, 112, carries a horizontalor lateral deflection yoke 114; and is also shown with a conventionalvertical deflection yoke, 115; but for the purposes of the present casesuch vertical deflection yoke need not be used. The lateral deflectionyoke serves to produce controlled lateral swings of amplitude needed toproduce or scan the cross-scans of desired width across the tape. Thecontrols for producing such lateral scans need not be detailed here,beyond stating that such a control as a conventional sawtooth generatormay be used for producing such lateral swings, at such rate as neededfor the intended operations. In the case of recording picture signalsfor television programs such lateral swings will, according to presentF.C.C. regulations, be at the rate of 15,750 scans/sec.

Extended through the broad end of the envelope there is provided ayseries of electrical conductors whose upper ends (within the envelope),186a in FIGURE 3, and 186k' in FIGURE 10, extend at uniformly spacedpositions along the target area which is scanned by the electron beam.It is here noted that such inner envelopeupper conductor ends are ofvarying lengths so that their tips, which are impacted by the electronbeam during each scan lie substantially in a circular arc drawn aboutthe center of beam deflection. Accordingly, it is not necessary tochange the focal length of the beam during scan, in order to ensure thateach of the conductors will be impacted by the focus of the beam, andthus with maximum electrical effect on the conductor.

As the beam comes successively into engagement with each of theconductors of the series, an electrical discharge effect is produced onsuch conductor; so that if such conductor be connected to a unit whichis in turn supplied by current of proper potential and polarity, acurrent ow will occur from such conductor to the electron beam and thusto the gun end of the electronic unit. It is noted that in each offigures such gun is shown at 113, and so legended.

The showings of FIGURES 1 to 7 disclose a convenient embodiment of thepresent inventive features in a unit for producing recordings on thetape; and the showings of FIGURES 8 to 14 disclose a convenientembodiment of such inventive features in a unit for sensing recordingsalready cross-scanned on the tape. It is here noted, however, that theembodiment of FIGURES 1 to 7 may also be used for sensing previouslyrecorded signals and that the embodiment shown in FIGURES 8 to 14 mayalso be used for producing recordings; but as will presently appear,such two embodiments are primarily intended for production of thefunctions stated at the beginning of this paragraph.

In the embodiment of FIGURES 1 to 7, inclusive, there is provided aseries of minute coils 191a corresponding to the ends of the conductors186 outside of the envelope, such minute coils being supported inregular succession close to or even in light contact with the surface ofthe tape, and along the line of scan to be produced. In this connectionit is noted that, although such minute coils are shown in FIGURE 5 asextending along a line parallel to the lower end portion of theenvelope, and thus at right-angles to the center line of the tape (seeFIGURE 1 wherein such lower envelope portion is shown at right-angles tothe tape center line), still, due to the endwise travel of the tapeduring recording, each scan produced on the tape actually extends acrosssuch tape at a slight angle, as shown in FIGURE 1. One end of each suchcoil is connected to the outer envelope end of the correspondingconductor. Also, such coils are thus supported with their axes extendingnormal to the tape surface so that the magnetizing eifect produced byeach coil during current flow through its helix (produced by theengagement of the electron beam with the inner end of its conductor)will act directly on the magnetizable material of the tape, and thusproduce a recording of strength proportionate to the strength of theelectron beam at the instant of engagement with such coils conductor.Thus, during successive beam scans there will be produced successivecross-scans of magnetized elemental areas, each such area beingmagnetized proportionately to the strength of the electron beam at theinstant of engagement with the conductor of the corresponding coil.

The free ends of all such coils (outside of the envelope) are connectedto the line 192 (see FIGURES 6 and 7), which, in turn is connected tothe proper portion of the circuitry for current supply to the coils.

In order to support these minute coils rmly, and to retain them in goodhelical form and in desired position close to the tape surface, they maybe embedded in a block of such material as synthetic moldable plastic,such as the block 193, FIGURES 6 and 7, and such block may in turn besecured by the ange plate 194 to the face of the lower portion of theenvelope of the electronic unit.

Referring next to the embodiment shown in FIGURES 8 to 14, inclusive,this embodiment is intended primarily for sensing the previouslyrecorded signals, for amplification and translation according toconventional or other operations. In this case the conductors extendfrom the interior of the envelope downward through such envelope, andhave their lower outside end portions carried down close to the tapesurface, and then formed into direction transverse of the tape width, toprovide sensing elements extending to right-angles to the direction oftape travel,

and thus in position to cut the lines of force from the magneticallyproduced elemental areas of the tape. Such right-angularly extending(transverse) portions are indicated at in FIGURES 11 and 12. Then suchsensing elements are extended upwardly far enough for connection to thecommon line 196 (see FIGURES ll, 12, 13 and 14). Such line may then beconnected to the proper elements of circuitry for translation of thesensed signals.

With this arrangement, the contact of the electron beam with the innerend portions of such conductors in succession during lateral scan of thebeam, will complete circuits of the successive conductors. As each ofthe conductors is thus brought into the sensing circuitry, the producedin the element 195 of such conductor is effective to influence thesensing circuitry, for translation of such into the translatingcircuitry. The endwise travel of the tape during the short interval ofengagement of the electron beam with the inner end of such conductor,will develop such in such portion 195 of such conductor element.

Provision is made for amplifying the effects produced by such successivesensings of the magnetic elemental areas of the tape. To this end adynode or series of dynodes 197 (see FIGURE 13) is provided adjacent tothe inner Vends of the conductors 186b, spaced apart from such innerends, but so placed that the electron beam during scan will impinge eachof such dynode elements in turn (or will engage a single long dynodesuccessively at points opposite to each of such conductors), thusproducing a secondary emittion towards such conductor with correspondingampliflcation of the potential to which the conductor is subjected. Withthis arrangement there is also produced an electronic switchingoperation from the electron beam to each of the conductors insuccession, and with amplification during each such switching operation.

Examination of FIGURES 3 and 10 will show that the inner end portions ofthe conductors are not only brought into a circular arc formed about thecenter of beam deection, but that such inner end portions are alsobrought closer together than the actual spacing between the successiveconductors at the points where they extend through the lower end of theenvelope. Accordingly, there will be produced a somewhat continual sweepfrom each conductor to its successor in the beam scan with slightoverlaps of continuity from elemental area to elemental area scanned.The extent of such possible overlap will of course depend not only onthe closeness of the successive inner ends to each of other, but also onthe iineness of the focal point of the beam. Such neness will be muchenhanced by the circular arc arrangement of such inner end portions,since by this arrangement a better effect will be possible in theproduction of continuous focal length er1- gagement of the beam with thesuccessive conductor inner ends.

In the embodiment of FIGURES 8 to 14, inclusive there is showntheembedding of the sensing elements 195 into a block of such material asmoldable synthetic, but with the actual sensing portions 195 close to oreven in actual contact with the tape surface during sensing; in whichlatter case (actual contact with the tape surface) such sensing portions195 should be included at the actual bottom face of such block.

In FIGURES 1, 2 and 4 there is shown a magnetic preconditioner unitincluding the pole pieces 132 by which if desired, a uniform degree ofmagnetization may be applied to the tape prior to producing themodulated magnetizations thereon by the electronic recording unit. Bythis means it is possible to bring the entire surface of the magnetictape to a degree of magnetization such that the recordings will beproduced at a location above the zero magnetization point of thehysteresis curve of the magnetic material used; but also at a pointbelow the knee of such magnetizing curve.

When the sensing of previously recorded signals is being conducted, theelectron beam strength should be steady,

and not modulated, except for special purposes; so thatthe effectsproduced by the sensing of the successive elemental areas will bedirectly proportional to the strengths of the magnetism sensed at suchelemental areas.

The use of the term minute in defining the sizes of the magnetizingcoils 191a indicates a smallness proportional to the desired definitionof the signals being sensed. Thus, if the operation may be one in which,say, 31 elemental areas .are to be recorded and afterwards sensed duringeach cross-scanning operation (as shown in FIG- URE 5, for example), andwith a cross-scanning width of, say 2 inches, the successive coils maybe located at center to center distances of 9&5 inch. Much smaller coilsmay, however, be used, or larger ones if desired. lt is .also possibleto stagger the successive coils along the lineal scan, thus bringingtheir center to center points closer together than would otherwise bepossible.

What is claimed is:

1. A signal recording unit for producing magnetic signal recordings on amagnetizable tape, comprising a deflectable beam electronic unit,including an envelope, an elongated target` within said envelope, anelectron gun Within the envelope in position to emit an electron beam,means to produce lateral deections of the electron beam with thedeflections lying in a plane parallel to the target, a series ofelectric conductors extending through the envelope at successivelocations along the target and having their inner ends lying within aplane parallel to the plane of beam deflection and laterally displacedfrom said beam deflection plane, a dynode unit within the envelope andhaving its secondary emittion surface lying at an angle to the plane ofbeam deflection and intersecting said beam deection plane along a linesubstantially parallel to the inner ends of the conductors andconstituted to emit secondary emittion against said conductor inner endsin succession during beam deflections, means to support the deflectablebeam electronic unit with the conductor elements exterior to theenvelope in proximity to the tape surface, together with means inconnection with the outer ends of said conductors constituted totransfer magnetic force signals between the conductors and the tapesurface.

2. A signal recording unit as defined in claim 1, wherein the meanswhich are in connection with the outer ends of the conductors constitutemagnet elements responsive to currents owing through the conductorsduring secondary emittion from the dynode unit under electron beamimpact against the dynode unit.

3. A signal recording unit as defined in claim 2, wherein the magnetelements are embedded into a block of nonmagnetic material which isnon-conducting.

4. A signal transferring unit as defined in claim 2, wherein each magnetunit includes a current flow portion extending in direction non-parallelto the length of the tape, together with means to produce travel of thetape in the direction of its length.

5. A signal transferring unit as defined in claim 2, wherein the magnetelements comprise conductor coils with their convolutions substantiallyparallel to the tape surface.

References Cited by the Examiner UNITED STATES PATENTS 2,565,515 8/1951Pallnel 313-105 2,657,377 10/1953 Gray 178-6.6 2,947,809 8/ 1960 Karolus178-6.6

IRVING L. SRAGOW, Primary Examiner.

ELI J. SAX, Examiner.

1. A SIGNAL RECORDING UNIT FOR PRODUCING MAGNETIC SIGNAL RECORDINGS ON AMAGNETIZABLE TAPE, COMPRISING A DEFLECTABLE BEAM ELECTRONIC UNIT,INCLUDING AN ENVELOPE, AN ELONGATED TARGET WITHIN SAID ENVELOPE, ANELECTRON GUN WITHIN THE ENVELOPE IN POSITION TO EMIT AN ELECTRON BEAM,MEANS TO PRODUCE LATERAL DEFLECTIONS OF THE ELECTRON BEAM WITH THEDEFLECTIONS LYING IN A PLANE PARALLEL TO THE TARGET, A SERIES OFELECTRIC CONDUCTORS EXTENDING THROUGH THE ENVELOPE AT SUCCESSIVELOCATIONS ALONG THE TARGET AND HAVING THEIR INNER ENDS LYING WITHIN APLANE PARALLEL TO THE PLANE OF BEAM DEFLECTION AND LATERALLY DISPLACEDFROM SAID BEAM DEFLECTION PLANE, A DYNODE UNIT WITHIN THE ENVELOPE ANDHAVING ITS SECONDARY EMITTION SURFACE LYING AT AN ANGLE TO THE PLANE OFBEAM DEFLECTION AND INTERSECTING SAID BEAM DEFLECTION PLANE ALONG A LINESUBSTANTIALLY PARALLEL TO THE INNER ENDS OF THE CONDUCTORS ANDCONSTITUTED TO EMIT SECONDARY